Peptide Reference Desk
GHRP-2 vs GHRP-6 vs Ipamorelin: compare the receptor assays before the rankings
GHRP-2, GHRP-6 and Ipamorelin share growth-hormone-secretagogue research territory, but selectivity claims depend on the assay, species and comparator panel.
The comparison usually starts too late
Most pages begin by ranking GHRP-2, GHRP-6 and Ipamorelin by a desired outcome. A laboratory comparison should begin with receptor pharmacology. All three are discussed as ghrelin-receptor agonists or growth-hormone secretagogues, but “more selective” has meaning only when the receptor panel and assay conditions are shown.
What to extract from the paper
- Receptor construct, species and cell system.
- Agonist concentration range and potency metric.
- Reference ligand and positive controls.
- Which off-target or endocrine endpoints were actually measured.
- Exposure timing and sampling schedule.
A statement that one compound caused “less spillover” is incomplete if the study never measured the relevant hormones or used a different exposure.
Three names, three identity files
GHRP-2 and GHRP-6 are related synthetic secretagogues, not interchangeable catalog aliases. Ipamorelin has its own sequence and pharmacology. Each lot needs its own expected mass, LC-MS result, HPLC trace, content basis and counterion record.
| Weak comparison | Better comparison |
|---|---|
| “Strongest GH peptide” | Matched receptor or endocrine assay |
| Vendor side-effect chart | Prespecified measured endpoints |
| One HPLC percentage | Identity, purity and content as separate tests |
| Stack anecdotes | Controlled combination evidence, if any |
Where CJC-1295 fits—and does not
CJC-1295-related materials act through the GHRH-receptor side of the GH axis, whereas these secretagogues are discussed through the ghrelin receptor. That mechanistic distinction explains why they are grouped in combination searches. It does not prove that a combination is safe, effective or correctly formulated.
Verify with primary records
Use the primary paper, current regulator label or lot-linked analytical file for the claim it supports. A search result is a route to evidence, not the evidence itself.